Political, scientific and sociological debate over the past twenty years has converged on the topic of global warming and the effects of production and venting of so-called greenhouse gases, or gasses that trap heat in the atmosphere. The effects of greenhouse gasses can be seen in the melting of the polar ice caps, rising sea levels, increases in the global average yearly temperature, extremes in weather (such has really hot or cold temperatures), allergies, and the effects on certain plant and animal species.
Some gases are more effective than others in making the planet warmer. Of the three most abundant greenhouse gases in the Earth's atmosphere, namely, water vapor, carbon dioxide, and methane, each of these gases can remain in the atmosphere for different amounts of time, ranging from a few years to thousands of years. While all of these most abundant greenhouse gases remain in the atmosphere long enough to become uniformly mixed and distributed in the atmosphere, the emitting of methane into the atmosphere is of primary concern. Thus, in 2012, the Environmental Protection Agency (“EPA”) set a goal of reducing methane emissions by 40-45% from 2012 levels by 2025.
Methane is emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from livestock and other agricultural practices and by the decay of organic waste in municipal solid waste landfills. Methane is the primary component of natural gas, and is the principal greenhouse gas emitted by equipment and processes in the oil and gas sector; and, through leakage and venting during the process of drilling for oil and gas can have a serious effect on the atmosphere. While methane doesn't remain in the atmosphere as long as carbon dioxide does, it has far more devastating consequences to the climate because of how effectively it absorbs heat. In the first two decades after its release, methane became 84 times more detrimental than carbon dioxide.
More recently, the EPA has updated the New Source Performance Standards (or “NSPS”) for the oil and gas industry to add requirements that the industry reduce emissions of greenhouse gases and to cover additional equipment and activities in the oil and gas production chain. The final rule will accomplish this by setting emissions limits for methane, which is the principal greenhouse gas emitted by equipment and processes in the oil and gas sector. To that end, on May 12, 2016, the EPA finalized the first-ever national rule to directly limit methane emissions from oil and gas operations. The final NSPS is expected to reduce 510,000 short tons of methane in 2025, or the equivalent of reducing 11 million metric tons of carbon dioxide. At natural gas well sites, the NSPS has mandated new requirements for detecting and repairing leaks, and requirements to limit emissions from certain specified equipment types.
Despite the strong push to reduce methane emissions, there has been recent changes in the political landscape that have resulted in stays of certain requirements under the EPA rule. For instance, on Nov. 1, 2017, the EPA announced that it is issuing two notices of data availability related to the agency's proposed stays of certain requirements in the 2016 NSPS for the oil and natural gas industry. Nevertheless, the overall trends continue to be toward the significant reduction of methane emissions in the oil and gas industry.
One consideration for the reduction of methane emissions in the industry is in the capture and catalyzation of wellhead emissions. U.S. Patent Publication No. 2017/0120191 A1, for a Wellhead Emission Control System, published May 4, 2017 to Nurkowski et al. (hereinafter “Nurkowski”), describes a system for introducing vented methane to a catalytic heater assembly resident in a housing unit to break down the methane in the presence of oxygen into a less harmful carbon dioxide and water. Though carbon dioxide is also a greenhouse gas, its short-term effects are less harmful to the atmosphere than that of methane.
Thus, what is not appreciated by the prior art is that regardless of what methodology is utilized to “treat” the vented methane to meet government standards and/or industry expectations, if the system employed is susceptible to maintenance, degradation of effectiveness, or flow-through issues, then the system may actually vent or leak to a point where more harm than good is created by the system.
Accordingly, there is a need for an improved system for capturing wellhead emissions which will provide the benefit of breaking methane down and creating a set of “less harmful” components. There is a further need for a weatherization system that withstands the rigors imposed on a wellhead that is resident outdoors in often harsh environments, and allows an operator to monitor the operation of the wellhead.